Physical time and Time as we experience it

Why are these two so different?

A CLEFT BETWEEN the future and the past
the breath between tomorrow and today
the lonely isle or sandy, sea-locked cay
surrounded, compassed by the ocean vast
upon whose shore my soul is stranded, cast,
marooned and shipwrecked, spirit washed away
that bounded by horizon of the day
until I spied the telltale sail at last
a phrase’ turn that awaits its crowning rhyme
causality is intimate relating
the watches-of-the-night-denoting chime
to signal that the darkness is abating
for all good things will come to me in time
and I can make the flowers grow by waiting

— Max Leyf

The way physicists think about time includes built-in contradictions. No one denies this, and there is an extensive literature in the philosophy of physics, with little agreement.

The paradox most commonly addressed is that the thermodynamic “arrow of time” is nowhere to be found in the fundamental equations of physics. Thermodynamics is supposed to be a derived science, based on the microscopic equations of physics, which are fundamental. But the fundamental equations are exactly the same going forward or backward in time, while the derived equations (about increasing entropy) tell of irreversible change happening in one time direction.

We experience past and future as different. We have a sense of agency about the future, while we regard the past as set in stone. Where does the asymmetry come from? If the equations of particle physics are indeed the root of all reality, why, in our experience, is the forward direction of time so different from the backward direction?

But there is a bigger paradox, addressed only obliquely, if at all, by physicists. The most salient feature of our experience of time is that there is a “now”, distinguished from all other times. Essential to our conscious experience is a sense of moving through time. But this “now” is nowhere to be found, in all the equations and laws of physics.

“The Moving Finger writes; and, having writ,
Moves on: nor all thy Piety nor Wit
Shall lure it back to cancel half a Line,
Nor all thy Tears wash out a Word of it.”
― Omar Khayyám (tr Edward Fitzgerald)

You could pore through all the equations of physics — equations that work so well to describe everything from particles in a high-energy collider to the motion of galaxies — all these equations contain no idea of a special “present moment”. Our subjective experience of time as something that moves has no place in Newton’s equations that govern motion, and this remains true in quantum physics.

The sense of a moving “now” is so essential a feature of our experience that it is inseparable. Conscious awareness and the “flow of time” are parts of one concept, or different ways of speaking about the same thing.

It gets worse. Our conviction that “now” is special is powerfully reinforced by the fact that everyone we know experiences the same “now” that we do. For people who are close enough to interact with us, their “now” is the same as ours to within a millionth of a second, which is a time too short for our perceptual apparatus to distinguish. Communication at the speed of light connects any human to any other within a few hundredths of a second, which is right at the threshold of a time interval that our senses might perceive. In everyday conversations, time lags from the speed of sound are similarly in the range of hundredths of a second.

Absolute, true, and mathematical time, of itself, and from its own nature, flows equably without relation to anything external, and by another name is called duration: relative, apparent, and common time, is some sensible and external (whether accurate or unequable) measure of duration. — Isaac Newton

Our subjective experience is of a moving “now”. Einstein showed us that the subjectivity of time is relative, and he went further to opine that “now” is an artifact of our human condition, an illusion without physical significance. More recently, Julian Barbour has written articles and an entire book denying that time has any reality. This, in my view, is an extreme perversion of science. The purpose of science is to explain our experience, to make it comprehensible and (somewhat) predictable. When science tells us that there are no explanations to be had because our experience is an illusion, science is gaslighting us.

It’s tough to make predictions, especially about the future.
— Yogi Berra

It remains true in quantum mechanics that the equations themselves are symmetric with respect to forward and backward time; and yet, in practice, we always use the equations of quantum mechanics to predict the future from the past, never to “retrodict” the past from the future. This could be regarded as an extra, unstated rule in the foundations of quantum physics: The wave function must be used to predict probabilities of the future, but never of the past. This suggests a way in which quantum mechanics might offer a basis for a subjective “now”.

“Nothing ever happened in the past; it happened in the Now. Nothing will ever happen in the future; it will happen in the Now.” — Eckhart Tolle

Quantum mechanics famously requires “observers” to complete the theory. For each observer, observation happens in the subjective “now”. The choice of observation is akin to our feeling that we are free to direct our attention as we wish. It is by this choice that consciousness enters the physical world, and by which we assert our influence on the future.

Is there a relationship between quantum measurement and life that gives direction to physical time?

A thought I've entertained of late is to identify what we call "consciousness" with the sense of a moving "now". Observation is the means by which consciousness enters the schema of quantum physics. The Schrödinger equation tells how probabilities evolve between observations, but the human (or animal or plant) choice of what to observe shares with the equations a causal role in bringing the past forward to create a future.

We (and all of life) participate in creation by our presence as witness. In choosing the focus of our attention, we are participating in creating the future each moment. This is the physical significance of the "now".

There is a quantum phenomenon called the Inverse Zeno Effect by which repeatedly choosing what to measure can influence a quantum state to morph into a different state.

I suggest that the incorporation of consciousness into the foundations of physics invests time with its physical character — including causality and the increase in entropy — that separates one-way macroscopic physics from the time-symmetric equations of fundamental physics.

If this seems too distant for you to hang on to…

Background — if this is starting to make your head spin, I suggest reviewing what I have written about the quantum measurement problem in the past. More here and here.

If you’re at all interested in the conceptual replacement of a physical universe with a living universe at the foundations of science, I recommend reading the background. This is the subject of a book that I hope to complete this year, and I will be publishing excerpts on this Substack as I write them.

For those who are impatient, here is a much-too-condensed summary of a revolutionary reconception of the foundations of science.

• Quantum physics already contains a potential role for consciousness in the form of “the measurement problem” or “collapse of the wave function” (two names for the same thing).

• In the Princeton PEAR lab, Robert Jahn and Brenda Dunne established that mere thought can affect quantum probabilities from a distance, with no “physical” link between the person and the quantum system. (This finding was, on the one hand, so profound that it deserved a Nobel prize, and, on the other hand, so contrary to conventional physics that most physicists won’t even look at their experiments.)

• There are hints that it’s not unique to humans — animals and even plants can do this.

• Though the effect Jahn and Dunne found was small, they were working with distracted experimental subjects, who volunteered for a boring task and had no stake in the outcome. It is a reasonable extrapolation that within our bodies, the effect of intention on probabilities is much larger. We have skin in the game, and as babies, we learn to use our intention to control brain and body in detail. My hypothesis is that the Jahn-Dunne effect explains the fact that our intention is able to create thoughts in our brains and movement in our muscles.

What happens when different people are observing the same system?

Our perceptions are individual. Our “now” is individual for each of us, and Einstein taught us just how different time can be for different observers. And yet, there is a consensus reality. To a great extent, I can speak to you about events in the world and I can count on your potential to verify them. It is (mostly) one, objective universe out there, and different observers can pool their observations to create a composite reality.

If physics tells us that each observer is influencing the physical world by the choices she makes in what to measure and what to pay attention to, our experience tells us that, collectively, we are creating a consensus reality by communicating and combining the results of our observations.

The way in which we combine observations to create a consensus reality is an open question that science has glossed over. The best-known reference to this question is from Eugene Wigner, a Nobel laureate and second-generation quantum physicist. He posed the question in the form of a paradox that has become known as “Wigner’s friend”. The point Wigner makes directly is that when we consider the human brain from the outside as a quantum system that we can query with measurements, we encounter paradoxes. The larger point is that the way to combine information from different observers is an unresolved question in the foundations of physics.

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If you are still bewildered, this essay has had its intended effect. Physicists work intimately with time as a parameter, but don’t understand our experience of time, and may even be inclined to deny our experience because they consider their equations more real than our perceptions. Studying the paradoxes and contradictions in a theory is often a fruitful path toward transcending the present theory with a broader, more encompassing paradigm. The ideas on this page are an invitation to that project.